The present invention relates to new and distinct cultivar of Ice Plant, botanically known as Delosperma, and referred to by the cultivar name ‘White Nugget’.
The new cultivar was selected from seedlings which resulted from a cross of Delosperma ‘Gold Nugget’ with an unknown variety of Delosperma, and was selected because of its pure white color and exceptional cold-heartiness.
The new cultivar was first discovered by Kelly Grummons in 1996 at Paulino Gardens of Denver, Colo. It was then asexually reproduced in 1997 by Cheryl J. Vestal at Paulino Gardens. Asexual reproduction of the new cultivar by terminal cuttings has shown that the unique features of this new Delosperma are stable, and are reproduced true to type in successive propagations.
The unique characteristics of ‘White Nugget’ have been repeatedly observed and are determined to be basic characteristics of this cultivar, which in combination, distinguish this Delosperma from other Delosperma species, such as the cultivar Delosperma ‘Gold Nugget’.
An interesting characteristic of this new variety is its low, compact spreading habit. ‘White Nugget’ is consistently lower and more dense-growing than the other commonly grown Delospermas commercially available and known to the inventor, such as D. cooperi, D. nubigenum or D. foribundum. 
Another interesting characteristic of the new variety is the pale foliage. ‘White Nugget’ has slightly less pigment in the foliage than other ice plants, like many albino sports.
Another interesting characteristic of the new variety is the pure white flowers. Flowers of ‘White Nugget’ are pure white and do not contain any other pigment. All other commonly cultivated Delosperma are pink or an impure white. In addition, other varieties of Delosperma that display white flowers do not display cold-heartiness and are also somewhat shrubby in appearance. These other varieties are easily distinguishable from the new variety described herein.
Another interesting characteristic of the new variety is its exceptional cold-heartiness. ‘White Nugget’ exhibits unusual cold tolerance when compared to other Delosperma species, exhibiting hardiness to at least 20 degrees Fahrenheit below freezing.
Another interesting characteristic of the new variety is its early flowering season. ‘White Nugget’ produces blooms in early spring and they last until well into the summer. They bloom much earlier and also bloom much longer than any other variety of Delosperma, known to the inventor, except for ‘Gold Nugget’.